Lets play guess the noise?

esckalayd · 07-21-2014, 05:30 PM

Ok fellow BMW owners, what they hell is this noise? I heard it today coming home from work and it appears to sound like a bad pulley or belt. I took it to a good indy guy who does work on my car and he mentioned it sounded like the a/c compressor when he put his EARS tool up to it and also set a screwdriver on it to feel the vibration. The problem is, that this noise and vibration was carrying through the whole system. If you put the screw driver on the housing near the top pulley it vibrated as well.

Two things to note, when i turned the AC off, the noise would go away while driving but come back at idle. The other thing, when i popped the hood when i got home, it almost smelled like an electric motor overheating.

What are your thoughts?

Phil325i · 07-22-2014, 02:51 AM

My guess would be serpentine belt pulley/tensioner.

Efthreeoh · 07-22-2014, 06:06 AM

I was going to go with the alternator is about to go tits up based on the vibration, but then I listen to the video and I, with Phil, sounds like a idler pulley. Easy to diagnose, just pull the belat off (takes less than a minute). The spin the pulleys on the tensioner and idler spots. If they spin easily with a "grainy" feel, then its shot. I'd not drive it like that.

Good luck.

esckalayd · 07-22-2014, 07:18 AM

Thanks guys for the ideas. I definitely am not driving it now, it is sitting in my garage waiting for me to get a T60 socket head so i can remove the belt and test the pulleys. The car is just about to hit 60K and it seems like everything wants to go wrong now

. Would you recommend replacing all pulleys at once or just the problematic ones?

esckalayd · 07-24-2014, 03:08 PM

UPDATE: AC compressor shit the bed. AC compress/dryer , belt tensioner system, idler pulley all replaced with a new belt. The mechanic is recommending replacing the crankshaft pulley (I am assuming so we know all pulleys are new and replaced around the same time)

07-21-2014, 05:30 PM	#1
esckalayd Private 19 Rep 98 Posts Drives: 2011 MCB E92 M3 Join Date: Mar 2014 Location: Orlando iTrader: (0)	Lets play guess the noise? Ok fellow BMW owners, what they hell is this noise? I heard it today coming home from work and it appears to sound like a bad pulley or belt. I took it to a good indy guy who does work on my car and he mentioned it sounded like the a/c compressor when he put his EARS tool up to it and also set a screwdriver on it to feel the vibration. The problem is, that this noise and vibration was carrying through the whole system. If you put the screw driver on the housing near the top pulley it vibrated as well. Two things to note, when i turned the AC off, the noise would go away while driving but come back at idle. The other thing, when i popped the hood when i got home, it almost smelled like an electric motor overheating. What are your thoughts? __________________ Past Cars:- 2011 Monte Carlo Blue E92 M3 Current Cars:- 2011 LMB E90 M3 ZCP/CWP/6MT/NO Moonroof
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07-22-2014, 02:51 AM	#2
Phil325i Brigadier General 616 Rep 3,194 Posts Drives: E92 325i MSport Coupe Join Date: Apr 2012 Location: UK South East iTrader: (1) Garage List 2009 BMW 325i Coupe [6.00]	My guess would be serpentine belt pulley/tensioner. __________________ E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; 3 x chassis braces; diff brace; N53 V-brace; 034 subframe inserts; BMS clutch stop; BMS CDV; RE g/box mounts; Delrin shift bushes; Saikoumichi OCC; Cyba scoops; BMW Perf Exhaust; HEL s/steel brake hoses; M3 rear spoiler; Recaro Sportster CSs; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof/clear front
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07-22-2014, 06:06 AM	#3
Efthreeoh General 17309 Rep 18,733 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	I was going to go with the alternator is about to go tits up based on the vibration, but then I listen to the video and I, with Phil, sounds like a idler pulley. Easy to diagnose, just pull the belat off (takes less than a minute). The spin the pulleys on the tensioner and idler spots. If they spin easily with a "grainy" feel, then its shot. I'd not drive it like that. Good luck.
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07-22-2014, 07:18 AM	#4
esckalayd Private 19 Rep 98 Posts Drives: 2011 MCB E92 M3 Join Date: Mar 2014 Location: Orlando iTrader: (0)	Thanks guys for the ideas. I definitely am not driving it now, it is sitting in my garage waiting for me to get a T60 socket head so i can remove the belt and test the pulleys. The car is just about to hit 60K and it seems like everything wants to go wrong now . Would you recommend replacing all pulleys at once or just the problematic ones? __________________ Past Cars:- 2011 Monte Carlo Blue E92 M3 Current Cars:- 2011 LMB E90 M3 ZCP/CWP/6MT/NO Moonroof
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07-24-2014, 03:08 PM	#5
esckalayd Private 19 Rep 98 Posts Drives: 2011 MCB E92 M3 Join Date: Mar 2014 Location: Orlando iTrader: (0)	UPDATE: AC compressor shit the bed. AC compress/dryer , belt tensioner system, idler pulley all replaced with a new belt. The mechanic is recommending replacing the crankshaft pulley (I am assuming so we know all pulleys are new and replaced around the same time) __________________ Past Cars:- 2011 Monte Carlo Blue E92 M3 Current Cars:- 2011 LMB E90 M3 ZCP/CWP/6MT/NO Moonroof
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